To accomplish the Date/Time answer comparison you would need to take the following steps:
1) Add an Event to your Page that runs on beforeSubmit and has a Custom Action. This event will call a custom function called DateTimeCompare(); Note that you will need to pass your End Date and Start Date questions into this function. Therefore the syntax would be: DateTimeCompare('End Date','Start Date');
2) Add the following to your Custom Header Content (this defines the custom function called in step 1:
//The End_Date and Start_Date values below are variable vales for the End Date and Start Date Questions which are passed to this function
//when the function is called on the Before Submit action. This means that the only change required to this code is the Alert/error message.
//Note that these variable values can NOT have spaces and therefore the spaces have been replaced with underscores.
var startDateFinal = new Date(startDate);
var endDateFinal = new Date(endDate);
// Finally, we check to see start date is greater than the end date.
// Personalized message to the user that date is not acceptable
alert(Start_Date+' value must be before ' +End_Date+ ' value.');
return false; //A return value of false will stop the submit process
Once these actions are completed this function will ensure that the Start Date value is Less Than the End Date value.